js怎么发送邮件啊！我这个填完了都发不了

我这个在网上找的，填完了也用不了，不知道为什么，能帮忙解答一下吗？

写个按钮,调用这个函数

    function sendEmail() {
      Email.send({
        Host: "smtp.gmail.com",
        Username: "sender@email_address.com",
        Password: "Enter your password",
        To: 'receiver@email_address.com',
        From: "sender@email_address.com",
        Subject: "Sending Email using javascript",
        Body: "Well that was easy!!",
        Attachments: [
          {
            name: "File_Name_with_Extension",
            path: "Full Path of the file"
          }]
      })
        .then(function (message) {
          alert("Mail has been sent successfully")
        });
    }

一般都是 后端实现，前端只把 发送内容 ，发送的邮箱，发送 人邮箱等参数传过去。后端一般 也是调用的 第三方的api ,而且大概率要收费